Answer:
A. The United States viewed Communist aggression in Korea as dangerous to other non-Communist states in Asia.
Step-by-step explanation:
The Korean War is the result of the veiled dispute between the United States and the former USSR, former allies during World War II. By the end of this period, in 1945, these countries divided Korea into two zones of influence, with the south occupied by the Americans and the north dominated by the Soviet Union. Both are divided by the 38th Parallel, established as a divisive landmark at the Potsdam Conference.
The involvement of the United States in this conflict is explained by the fact that the Soviet Union established itself north of the Korean peninsula after the expulsion of the Japanese colonies. Fearful of a possible Communist influence that the Soviet Union could establish in Asia, the United States decided to involve its troops in the conflict and make sure to contain Communism in that region.